Hoosier R6 looses traction at the track

[VNM]

Had the Hoosiers R6 installed all around on my Gen 4 viper and took it to the track. The tires are precise when turning, but the car looses traction coming out of corners in 2nd gear !
Is there a better tire out for the 18/19 setup ? Or should I go with a 18 all around setup for more tire options?

Car mods: 2008 viper
Mopar PCM
Belanger header
Corsa exhaust
3.5 quaife diff
BBG ported lower intake
BBG Clutch

614WHP - not sure of torque


Thanks,

Moe

 

[Jay Lopez]

I ran those on 17/17 on my gen 2. Once I got them warmed up, they were awesome. If you are not getting them warm, they are loose. You might need to adjust tire pressure to force them hot sooner. I used to also swing left/right on the warm up lap to use the friction to create heat.

 

[Allan]

Viper with 3.55 rear gear is gonna have traction issues in 2nd gear no matter what the tire or temp is.
Mine is a near stock gen III with R6's, 3.07 gear. I can break traction and get the car loose out of a corner in 2nd with the tires at temp.

Remember, this is a car that is pissed-off. It requires lots of driver control. You are the traction management. there is nothing wrong with the Viper or the tire choice. (A6's are softer and R100's are full race slicks, but really the R6 is killer enough)
Part of the fun of driving such a car at the limit on the track is just that. Managing the monster car. -Viper.....Skilled handler required.

If you want a car that is 'point and shoot' without the chore of having to be diligent with throttle input, get a GTR. The computers will manage the traction for you.
I've tracked other cars, and find them boring in comparison. The Viper demands 100% driver attention at all times, and makes you work to be smooth and fast. Cannot just bang the throttle on like in other cars. Have to 'squeeze or roll-on' the throttle out of the corner while unwinding the steering wheel. Fine balance of driver traction management to avoid losing it into the weeds. Very rewarding when done well. -Intoxicating.

Don't be disappointed in the car or the tires. Learn to adjust your driving technique to get the most out of yourself and the Viper.
Not many will be able to keep up.

 

[mjorgensen Woodhouse]

I better suspension would help with weight transfer as would a proper corner weight and track oriented alignment if you don't already have one. I have run 3.07, 3.55 and 3.73's with similar power and although you can still break loose even in 3rd if you hack at it, the progression to oversteer is more managable with proper set up. Check tire pressures also, if you are too high the break away will be very abrupt. Sometimes running a little lower pressures in the rear help with compliance and feel at bigger slip angles.

 

[Dom426h]

+1 Allen

This could just be a complaint about the lack of traction control which in a drivers car like the viper is the responsibility of the driver. Could be something as simple as gear selection. Perhaps 3rd gear is better suited for the corner he is loosing control in. Or maybe just rolling on the throttle to much too soon. Maybe not rolling on it at all, just getting crazy with it and expecting to be able to put the foot to the floor as soon as he passes the apex and see's the next straight.
It is possible that his setup is off though...


+1 MJ

- If he is running a stock or stockish alignment that could be the issue right there.
- On the suspension, I don't know how people track cars with soft stock springs.
The ACR & aftermarket setups run Twice the spring-rate over stock which is
much more predictable & precise for cornering.

 

[mjorgensen Woodhouse]

+1 Allen

This could just be a complaint about the lack of traction control which in a drivers car like the viper is the responsibility of the driver. Could be something as simple as gear selection. Perhaps 3rd gear is better suited for the corner he is loosing control in. Or maybe just rolling on the throttle to much too soon. Maybe not rolling on it at all, just getting crazy with it and expecting to be able to put the foot to the floor as soon as he passes the apex and see's the next straight.
It is possible that his setup is off though...


+1 MJ

- If he is running a stock or stockish alignment that could be the issue right there.
- On the suspension, I don't know how people track cars with soft stock springs.
The ACR & aftermarket setups run Twice the spring-rate over stock which is
much more predictable & precise for cornering.

Yes we use double the rate springs, but still have 100% better ride (we have even replace shocks and springs on an ACRX and he says the car is much faster then he can drive now so he's relearning the limits), the stock shocks are so stiff the rates don't seem to matter, the MCS is so much more efficiant that the control is smoother and the other big part is its ability to go to a bypass when a sharp bump (high speed compression event) is encountered. This bypass action for compression is what gives the MCS so much more mechanical grip, most other brands do not have this.

 

[TRACKDAY]

There's nothing wrong with the Hoosiers. They're very good track tires.

Allan and Mark are both correct. Throttle input is key in pushing a Viper. It's very easy to induce power oversteer coming out of a slow corner, especially in 2nd gear.

The Viper's throttle wasn't designed to be like an "on / off" switch. It requires smoothness and "rolling on the power" coming out of a corner. In a Viper, you should never simply stomp on the throttle. That's asking for a disaster to happen.

Randy Pobst said it best when he tested a Viper a few years ago. He said, "In most cars, you have to be smooth with the throttle for only the first few laps. In a Viper, you have to be smooth with the throttle ALL THE TIME." He was exactly right.

Stick with the Hoosiers and try different ways of applying the throttle coming out of slow-ish corners....you'll be pleasantly surprised.

Good luck

 

[bluesrt]

trackday is key on----------------

 

[VIPER GTSR 91]

What Mark said above is spot on. I run the R6 on my 09 ACR with great results BUT with OZ 18s all the way around. Less weight and slightly lower to the ground. There can also be quite a few variables on how you corner exit or track out with the car.

 

[VNM]

Thanks guys i guess ill play around with the tire pressure next time and try to ease on the throttle like you guys said.
By any chance would anyone remember the what the tire pressure should be on the A6 when its cold?

 

[Allan]

I have been happy with 34 front / 32 rear, cold.

Different people seem to have different preferences with what works best. Depending on car setup, track, ambient temp, and whatever other variables on any given day. Most guys run a little more in the fronts though.

 

[VIPER GTSR 91]

Thanks guys i guess ill play around with the tire pressure next time and try to ease on the throttle like you guys said.
By any chance would anyone remember the what the tire pressure should be on the A6 when its cold?

The A6 is an autocross tire but for the R6 start with 32 front and 28 rear COLD for road racing.

 

[Stuntman]

What hot pressures do you shoot for?

 

[Allan]

The A6 is an autocross tire but for the R6 start with 32 front and 28 rear COLD for road racing.

See, here's what works for this guy................................

4PSI difference between front and rear......wow.

 

[Allan]

What hot pressures do you shoot for?

I don't shoot for any target hot pressure anymore.
Gave up on that approach along time ago.
Have settled on my cold pressure settings by many trial and error sessions of adjusting up and down a pound at a time.
Adjustments made by feel of the car throughout each day/session and tire wear characteristics.
I also am running the 275 front tire if that makes any difference.

Different drivers, different cars, different opinions,........whatever works for each guy is personal preference.
Pay more attention to the advice from the faster more consistent drivers when you are at the track.
.......usually, the guys running around their car every 5 minutes with a damn pressure gage, freaking out on their hot this, and their cold that, and left and right front/ back whatever, ......aren't that quick.

And they are the guys that seem to think their problem is due to not having the tire pressure dialed in.

One of the clubs I run with has a guy like this. He drives a P-car.
He is slow around the corners, and he thinks it's due to not having his pressures dialed in -ever, apparently.
Nothing to do with is ugly jacked-up line, and not knowing where to place the car at any given part of a turn.
Comes in at least 3 times in a session to adjust his stupid tire pressures. -never seems to make any difference as far as I have noticed.
Been lapping this guy for years.............he always asks about my tire pressures (wondering what the secret is to getting around the corners so fast).
I tell him 'I don't have any idea, I haven't checked it in months'.

 

[Boxer12]

You should download and read this, there is good info: http://www.tirerack.com/images/pdf/warranty/HOOSIER.pdf. "OVER 3000 LBS. Hot=34-39+ Cold=23-29..+Higher pressures will improve the performance capability but will require a more sensitive feel to take advantage of the increase. One characteristic of the tires is the tendency to “skate” initially (when inflation pressures are correct). It is important to resist lowering the pressure to attempt to eliminate this feeling. Dropping the pressure too far may improve the “feel” of the tire however it will also lower the performance and increase the wear rate."



FWIW, I start out cold temps of 28 all four with R6's and don't push the car to the limit until lap 5 or 6 on a 2 mile circuit with hard corners and acceleration/braking zones. These tires will not grip until they are at a significantly higher temperature than an A6. The tires will typically gain about 8-10 psi by that time. By the time you get to the pit stall, or unbuckle and get out of the car, the temps will change so you need to have a buddy check hot temps in the hot pits. Just check them to make sure they are all even when back in the pit stall, and work from there if you want to add some feel. Eg., you can lower pressure on the rears if you want to feel the tire give away sooner.

With A6's, I start out about 24 all four, but I run them to get a fast first lap in time trial competition. After two hot laps, the temps are up and the tire is slick so I am done. R6's get grippier after 2 laps, but them after about 8 laps they get real greasy. A6's will get greasy sooner but them become grippy again, so you get good first laps and late laps with them when racing. R6's will build speed then lose speed over a 30 min race session. You will get your best laps in the middle of the session with an R6.

What Mark said is very true about setup and handling. That is more of an advanced issue when you are squeezing seconds (or tenths in the case of a really experienced and talented (consistent) driver), although dampers will cost less in the long run to improve your performance since they are changed once whereas you will be putting on Hoosiers every other weekend or so whether you are getting the most out of them or not. A good test is to see if you are getting better times than with PSC's (also an R6 compound). If not, then you aren't getting the performance out of the tire. Also, 305's up front are faster than 275's in any situation except straight line speed so unless you just want max speed on the straights, go with them. Just my 2c.

 

[Dan Cragin]

I run 24-25psi cold and shoot for 34psi hot. Anything more than 36 hot and the R6's get greasy.

 

[Stuntman]

Hot pressures are all that matters. Setting your tires at X cold psi at 60* ambient will yield different hot pressures than at 100* ambient. Also driver to driver and how quickly various tires get up to temp and overheat will also vary, so the goal is to target an ideal hot pressure for a given tire and setup.

 

[Boxer12]

Here is the problem, although I suspect this won't be an issue for HPDE guys (if that's what you are doing). Hot pressures are ideal, but if you are setting yourself, and you go back to your pit and check them, then they will be inaccurate and too high when they get back to running temps. That's why you see the teams checking pressures in the hot pits (and its not the driver doing it). Tire temps change from the track to the pits. "Hot" pressures means running temps not 'after you get back to the pit stall' temps. You obviously have to set them cold unless you have heating blankets, and its a starting point to record and work from on future days. When you get back to the pit stall, check them for sure but realize the temps will increase from whatever you set them at, when you running hard, and the increase will be variable. You will also notice that every time you come back to the pits your temps will vary, as will the surface temps on your tires (inner and outer) if you are checking that. Bottom line is you can spend all day fussing with tire temps (which a lot of guys do for the 'art' of it) or you can set them cold and leave them alone until the next day (adjust for feel or times until you figure out the best setting for your track). I set them cold (based on my track logs) and seem to be able to occasionally set track records with that method (Tommy Archer's advice actually), because I don't have a crew to check them in the hot pits.

 

[Stuntman]

I'm not saying that method does not work, I'm just looking for the ideal hot pressures before the tires balloon up and lose grip.

Ideally you have a friend w.a gauge or pull into the hot pits without a cool down lap once the tires start to get greasy, and check the pressure and bleed them down a bit. But your method of trial and error and bleeding them down a bit in the cold pits and seeing how that new pressure change affects the pressure buildup and feel during a session also works.

So ~36psi hot is pretty much in line with most "standard" sized street/rcomps that I've run (36-40, and even 42pai hot depending on the car/weight/tire).

I would have guessed they would have been a little lower due to the large sized tires, especially with tires with stiffer sidewalls. When you first go out at 28psi, how does the tires feel on lap 2-3 compares to say, lap 7&8?

 

[FrankBarba]

Stuntman....F it....forget air & go with Nitrogen....Now you can ask a whole set of new questions.
how does the tires feel on lap 2-3 compares to say, lap 7&8?
What track are you lapping on ? what is the outside temperature ? What is the relative humidity ? What are your spring rates,
are your shocks adjustable....Forget about the Hoosiers, use your street tires to get a real feel for your ride....This is
what i would suggest.
And 2nd Gear will break loose tires on most road courses. Try 3rd gear lots of Torque, bet you won't break your tires loose.
I can tell you how my car feels but its my driving style not yours. Go to the track ask lots of questions what you don't
want to keep, file in the trash. Your Porsche Driver sounds like he is more concerned with keeping his tires in good shape,
not trying to fly around the track.

 

[Stuntman]

...just curious on your comments of the grip, squirm, and response differences between your cold and hot pressures.

I've been on a few tracks, just looking for viper specific information since there aren't many people who track their cars or discuss setups compared to other communities.